A battery cooling system of an eco-friendly vehicle such as a hybrid vehicle, an electric vehicle, a fuel cell vehicle, or the like is operated to cool a battery at a predetermined temperature to maintain the battery at optimal performance. A battery cooling system according to the related art has a structure in which a cooling fan relay connected to an auxiliary battery power supply, a motor driving controller, and the like are integrated in a cooling fan motor controller.
Particularly, a battery management system (BMS) is connected to the relay and the motor driving controller of the cooling fan motor controller via a wire. Therefore, when the wire is disconnected, it is impossible to perform an ON/OPP control for the relay and it is impossible to transmit a speed control signal (e.g., a pulse width modulation (PWM) signal) to the motor driving controller. In addition, when the relay of the cooling fan motor controller is turned on/off in a normal state, noise may occur. An expensive rotation speed sensor of printed circuit board (PCB) type configured to sense motor speed is separately mounted in the cooling fan motor controller, which causes an increase in cost for manufacturing the battery cooling system.